Rotary worm and platewheel pumps



Oct. 13, 1964 c. K. HAMMILL ROTARY WORM AND PLATEWHEEL PUMPS 2 Sheets-Sheet 1 Filed May 1, 1963 INVENTOR'.

CHARLES K. HAMMILL ATTORNE S Oct. 13, 1964 c. K. HAMMILL 3,152,550

ROTARY WORM AND PLATEWHEEL PUMPS Filed May 1, 1963 2 Sheets-Sheet 2 ////////I/A I 7/// InvEN ToR:

CHARLES K. HAMMILL BM SL271 M A T roRn-EYs United States Patent ROTARY WORM AND PLATEWHEEL PUMPS Charles Kenneth Harnrnill, North Roshear, Camhorne,

England, assignor to Goodyear Pumps Limited, Camborne, England, a British company Filed May 1, 1963, Ser. No. 277,200 Claims priority, application Great Britain May 3, 1962 '7' Claims. (Cl. 103125) The present invention relates to notary Worm and platewheel pumps in which a rotor comprising a pumping Worm is rotatable in a bore in a rotor casing and meshes with a peripherally notchai rotatable platewheel which extends into the bore through an axially extending slot in the casing.

According to the present invention a rotary worm and platewheel pump comprises a pump casing, a bore in said casing serving as a rotor chamber, a rotor incorporating a pumping worm in said bore, an axially extending slot in the casing communicating with said bore, a peripherally notched platewheel extending into the bore through said slot and meshing with the rotor, said slot being bounded at opposite sides by axially extending walls which face opposite sides of the platewheel and are spaced apart so as to leave a gap between the platewheel and at least one of them, a fillerpiece filling said gap and detachably secured to one of said walls and having an inner surface shaped to form part of said bore, said fillerpiece being insertable in said gap after the platewheel has been meshingly engaged with the rotor, a platewheel Y enclosing cover detachably secured to the casing and means for rotatably supporting the platewheel in mesh with the rotor.

The axially extending slot is thus wider than is necessary to provide a running clearance therein for the platewheel and its etfective width is reduced to that required for a running clearance by at least one fillerpiece which on assembly of the pump is capable of being inserted after the platewheel has been brought into mesh with the rotor.

In a preferred form of construction the effective width of the axially extending slot is reduced by two fillerpieces located one at each side of the platewheel.

Threaded holes may be provided in the fillerpiece or filierpiecse to register with clear bolt holes in the casing extending outwardly from said wall or walls of the slot so as to enable the fillerpieces to be held in position in the slot by setbolts which can be manipulated from the exterior of the casing.

The platewheel may be rotatably supported by a spindle which extends across and is supported by the platewheel cover.

The pumping worm of the rotor is preferably parallel sided or substantially so i.e. of substantially uniform width from root to tip, and the notches in the platewheel are in the form of parallel or substantially parallel slots corresponding to the parallel sided cross-sectional form of the worm. With pumps of the type with which the present invention is concerned it is impossible, if the worm is substantially parallel sided and if the notches in the platewheel are of corresponding substantially parallel slot-like form, to advance the platewheel into mesh with the rotor whilst maintaining the plane of the platewheel so that it contains or is parallel to the axis of the rotor. To bring the two into mesh it is necessary to turn the platewheel temporarily to a position at which its plane is at an angle to the axis of the rotor. To do this would be impossible if the rotor casing were formed in one piece and if the slot in the casing were merely sufficiently wide to afford a running clearance for the platewheel. For this reason some worm and platewheel pumps have been provided with rotor casings formed in two parts meeting in a plane or planes passing through the bore of the pump. The present invention permits of the use of a parallel sided worm without recourse to a pump casing which is split across the bore.

in order to increase the extent to which the platewheel whilst being entered into mesh with the rotor, can be angled relatively to the axis of the rotor a groove may be provided in each of said slot walls adjacent diagonally opposite ends thereof, the grooves being of decreasing depth toward and stopping short of the bore of the casing.

If desired an elastomer facing may be provided on the flank of the fillerpiece or of each of said fillerpieces adjacent to the platewheel.

The invention is further described by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is an exploded perspective View of one form of P p,

FIG. 2 is a sectional side view of a pump substantially similar to that of FIG. 1 taken on the line HII of FIG. 3;

FIG. 3 is a sectional end View taken on the line IlIIlI of FIG. 2;

FIG. 4 is a view looking in the direction of the arrow A in FIG. 3 to illustrate the slot in the casing before meshing of the platewheel with the rotor;

FIG. 5 is a fragmentary sectional view taken on the line VV of FIG. 4 and FIG. 6 is a sectional view of a detail.

The pump casing it) has a rotor chamber or bore 11, ports l2, 13 at opposite sides of the bore and an axially extending slot 14 leading from the underside of the casing into the bore 11. A rotor 15 comprising a hub with a parallel sided worm 16 thereon fits in the bore 11 and meshes with a platewheel 17 which enters the bore 11 through the slot 14 and is formed with parallel sided slot-like notches 18 corresponding to the crosssectional form of the worm 16. The platewheel is arranged to rotate about an axis substantially at right angles to the axis of rotation of the rotor. The spacing of the notches 13 corresponds to the pitch of the worm 16. The profile 19 of the hub of the rotor 15 is circular and corresponds to the circular profile of the platewheel 17.

The width of the slot 14 which is indicated by the letter W in FIG. 3 is considerably greater than that requisite to provide a running clearance therein for the platewheel 17 but its effective width is reduced to that requisite for running clearance by means of a pair of fillerpieces or check plates 20, which are inserted between the sides 22 of the slot 14 and the platewheel 17.

Fillerpieces 26 are held against the sides 22 of the slot 14 by setbolts 24 which pass through holes 25 extending from the exterior of the casing to the slot 14 and which engage in threaded holes 26 in the fillerpieces. To prevent leakage along the setbolts 24 a sealing ring 27 surrounds each bolt 24 and is disposed in an annular recess in the outer face of the fillerpiece. The bolts 24 are preferably fitted bolts.

The platewheel is enclosed by a platewheel cover 3% secured to the underside of the casing 10 by setbolts (not shown) or by studs and nuts. The platewheel cover 30 is applied to the casing after the platewheel has been meshed with the rotor and after the fillerpieces 20 have been fitted. The platewheel is journalled on a spindle 31 having a head 32 and threaded neck 33 which engages in a threaded opening at the righthand side of cover 30 as viewed in FIG. 3. The opposite end of the spindle 31 is tapered at 34 and is supported in an opening 35 at the lefthand side of the cover 30, which opening is closed by a threaded nut 36. The spindle 31 is threaded into the platewheel cover 30 and through the bearing 37 of the platewheel 17 after the platewheel cover 30 has been fitted to the casing 10.-

FIG. 4 illustrates the slot 14 in the base of the casing 1t and the rotor 15 located in the bore 11 beyond the slot 14. The inclination of the plane of the platewheel 17 to the axis of the rotor as it is being advanced into mesh with the rotor is illustrated in FIG. 4. To minimise the width of the slot 14 but at the same time to allow for adequate inclination of the plane of the platewheel to the axis of the rotor to enable the platewheel to enter into mesh with the rotor grooves 40 are milled out of the side walls 22 of the slot 14 adjacent to diagonally opposite corners thereof. The grooves 49 extend over a portion only of the depth of the slot 14 (FIGS. 1 and 5) and thus do not extend into the bore 11.

The shape of the underside 42 of the fillerpieces 20, should be such as to enable the fillerpieces to be advanced endwise into the position shown in FIGS. 2 and 3 after the platewheel has been brought into mesh with the rotor. The end faces 44 of the fillerpieces 20 and the end faces 45 of the slot 14 lie on a cylinder of radius very slightly greater than the radius of the platewheel 17 (FIGS. 2 and 4).

The curved ends 4-4 of the fillerpieces 20 may be faced with a compressible or resilient material bonded thereto to provide a tight joint with the curved end faces 45 (FIG. 4) of the slot 14. The flanks of the fillerpieces 29 facing the platewheel may be faced with rubber or other elastomer.

The bore 11 of the casing may be lined with rubber or other elastomer. The lining may be bonded directly to the bore 11 or may be formed as a metal backed sleeve inserted in the bore 11.

I claim:

1. A rotary worm and platewheel pump comprising a pump casing, a bore in said casing serving as a rotor chamber, an inlet port and outlet port at opposite ends of said bore, a rotor comprising a hub with a substantially parallel sided worm thereon in said bore between the inlet port and outlet port, said worm extending over at least two convolutions, an axially extending slot in the casing communicating with said bore, a rotatable platewheel extending into the bore through said slot and having equidistantly spaced radially directed substantially parallel sided notches therearound, the platewheel being arranged to rotate about an axis substantially at right angles to the axis of rotation of the rotor so enabling the notches in the platewheel to mesh with the worm on the rotor with the portions of the platewheel between the notches extending into spaces between the convolutions of the worm to form partitions therein, the hub of the rotor being of longitudinal curvature corresponding to the peripheral curvature of the platewheel, said axially extending slot in the casing being bounded at opposite sides by axially extending walls which face opposite sides of the platewheel and are spaced apart so as to leave a gap between the platewheel and at least one of said walls, a fillerpiece filling said gap and detachably secured to one of said walls and having a surface shaped to form part of said bore, a platewheel enclosing cover detachably secured to the casing and means for rotatably supporting the platewheel in mesh with the rotor.

2. A rotary worm and platewheel pump comprising a pump casing, a bore in said casing serving as a rotor chamber, an inlet port and an outlet port at opposite ends of said bore, a rotor comprising a hub and a substantially parallel sided worm thereon in said bore between the inlet port and outlet port, said worm extending over at least two convolutions, an axially extending slot in the casing communicating with said bore, a rotatable platewheel extending into the bore through said slot and having equidistantly spaced radially directed substantially parallel sided notches therearound, the platewheel being arranged to rotate about an axis substantially at right angles to the axis of rotation of the rotor so enabling the notches in the platewheel to mesh with the worm on the rotor with the portions of the platewheel between the notches extending into spaces between the convolutions of the worm to form partitions therein, the hub of the rotor being of longitudinal curvature corresponding to the peripheral curvature of the platewheel, said axially extending slot in the casing being bounded at opposite sides by axially extending walls which face opposite sides of the platewheel and are spaced apart so as to leave a gap between the platewheel and at least one of said walls, a fillerpiece filling said gap and detachably secured to one of said walls and having a surface shaped to form part of said bore, the gap and said fillerpiece being shaped to enable the fillerpiece to be inserted in the gap after the platewheel has been meshingly engaged with the rotor, a platewheel enclosing cover detachably secured to the casing and means for rotatably supporting the platewheel in mesh with the rotor.

3. A rotary worm and platewheel pump comprising a pump casing, a bore in said casing serving as a rotor chamher, an inlet port and outlet port at opposite ends of said bore, a rotor comprising a hub with a substantially parallel sided worm thereon in said bore between the inlet port and outlet port, said Worm extending over at least two convolutions, an axially extending slot in the casing communicating with said bore, a rotatable platewheel extending into the bore through said slot and having equidistantly spaced radially directed substantially parallel sided notches therearound, the platewheel being arranged to rotate about an axis substantially at right angles to the axis of rotation of the rotor so enabling the notches in the platewheel to mesh with the worm on the rotor with the portions of the platewheel between the notches extending into spaces between the convolutions of the worm to form partitions therein, the hub of the rotor being of longitudinal curvature corresponding to the peripheral curvature of the platewheel, said axially extending slot in the casing being bounded at opposite sides by axially extending walls which face opposite sides of the platewheel and are spaced apart so as to leave a gap between the platewheel and each of said walls, fillerpieces filling said gaps and detachably secured respectively to said walls and each having a surface shaped to form part of the bore, the gaps and the fillerpieces being shaped to enable the fillerpieces to be inserted in the gaps after a the platewheel has been meshingly engaged with the rotor, a platewheel enclosing cover detachably secured to the casing and means for rotatably supporting the platewheel in mesh with the rotor.

4. A pump according to claim 3 comprising a platewheel supporting spindle extending across and supported by the platewheel cover.

5. A pump according to claim 3 comprising an elastomer facing on the flank of each fillerpiece adjacent to the platewheel.

6. A rotary worm and platewheel pump comprising a pump casing, a bore in said casing serving as a rotor chamber, an inlet port and outlet port at opposite ends of said bore, a rotor comprising a hub with a substantially parallel sided worm thereon in said bore between the inlet port and outlet port, said worm extending over at least two convolutions, an axially extending slot in the casing communicating with said bore, a rotatable platewheel extending into the bore through said slot and having equidistantly spaced radially directed substantially parallel sided notches therearound, the platewheel being arranged to rotate about an axis substantially at right angles to the axis of rotation of the rotor so enabling the notches in the platewheel to mesh with the worm on the rotor with the portions of the platewheel between the notches extending into spaces between the convolutions of the worm to form partitions therein, the hub of the rotor being of longitudinal curvature corresponding to the peripheral curvature of the platewheel, said axially extending slot in the casing being bounded at opposite sides by axially extending walls which face opposite sides 5 of the platewheel and are spaced apart so as to leave a gap between the platewheel and each of said walls, fillerpieces filling said gaps and each having a surface shaped to form part of the bore, the gaps and the fillerpieces being shapedto enable the fillerpieces to be inserted in the gaps after the platewheel has been meshingly engaged with the rotor, a platewheel enclosing cover detachably secured to the casing, means for rotatably supporting the platewheel in mesh with the rotor, bolt holes extending outwardly through the casing from said walls of said slot, internally threaded openings in said fillerpieces and bolts passing through said bolt holes and communicating with the threaded openings of the fillerpieces for detachably securing the fillerpieces to said walls.

7. A rotary worm and platewheel pump comprising a pump casing, a bore in said casing serving as a rotor chamber, an inlet port and outlet port at opposite ends of said bore, a rotor comprising a hub with a substantially parallel sided worm thereon in said bore between the inlet port and outlet port, said worm extending over at least two convolutions, an axially extending slot in the casing communicating with said bore, a rotatable platewheel extending into the bore through said slot and having equidistantly spaced radially directed substantially parallel sided notches therearound, the platewheel being so arranged to rotate about an axis substantially at right angles to the axis of rotation of the rotor so enabling the notches in the platewheel to mesh with the worm on the rotor with the portions of the platewheel between the notches extending into spaces between the convolutions of the worm to form partitions therein, the hub of the rotor being of longitudinal curvature corresponding to the peripheral curvature of the platewheel, said axially extending slot in the casing being bounded at opposite sides by axially extending walls which face opposite sides of the platewheel and are spaced apart so as to leave a gap between the platewheel and each of said walls, a groove in each of said slot walls adjacent diagonally opposite ends thereof, said grooves being of decreasing depth towards and stopping short of the bore of the casing whereby during meshing the platewheel into engagement with the worm the platewheel can be inclined to the axis of the rotor to a greater extent than determined solely by the width of said slot, fillerpieces filling said gaps and detachably secured respectively to said walls and each having a surface shaped to form part of said bore, the gaps and the fillerpieces being shaped to enable the fillerpieces to be inserted in the gaps after the platewheel has been meshingly engaged with the rotor, a platewheel enclosing cover detachably secured to the casing and means for rotatably supporting the platewheel in mesh with the rotor.

References Cited in the file of this patent UNITED STATES PATENTS 259,965 Wing June 20, 1882 983,365 Haskell Feb. 7, 1911 1,266,605 Madero May 21, 1918 1,735,477 Stuart NOV. 12, 1929 2,158,933 Good May 16, 1939 2,603,412 Chilton July 15, 1952 2,716,861 Goodyear Sept. 6, 1955 

1. A ROTARY WORM AND PLATEWHEEL PUMP COMPRISING A PUMP CASING, A BORE IN SAID CASING SERVING AS A ROTOR CHAMBER, AN INLET PORT AND OUTLET PORT AT OPPOSITE ENDS OF SAID BORE, A ROTOR COMPRISING A HUB WITH A SUBSTANTIALLY PARALLEL SIDED WORM THEREON IN SAID BORE BETWEEN THE INLET PORT AND OUTLET PORT, SAID WORM EXTENDING OVER AT LEAST TWO CONVOLUTIONS, AN AXIALLY EXTENDING SLOT IN THE CASING COMMUNICATING WITH SAID BORE, A ROTATABLE PLATEWHEEL EXTENDING INTO THE BORE THROUGH SAID SLOT AND HAVING EQUIDISTANTLY SPACED RADIALLY DIRECTED SUBSTANTIALLY PARALLEL SIDED NOTCHES THEREAROUND, THE PLATEWHEEL BEING ARRANGED TO ROTATE ABOUT AN AXIS SUBSTANTIALLY AT RIGHT ANGLES TO THE AXIS OF ROTATION OF THE ROTOR SO ENABLING THE NOTCHES IN THE PLATEWHEEL TO MESH WITH THE WORM ON THE ROTOR WITH THE PORTIONS OF THE PLATEWHEEL BETWEEN THE NOTCHES EXTENDING INTO SPACES BETWEEN THE CONVOLUTIONS OF THE WORM TO FORM PARTITIONS THEREIN, THE HUB OF THE ROTOR BEING OF LONGITUDINAL CURVATURE CORRESPONDING TO 